Toners and processes thereof

ABSTRACT

Disclosed are toner compositions comprised of a polymer, an optional colorant, and an UV light curable oligomer. Also disclosed are methods for producing a UV curable toner compositions, the toner compositions produced thereby, and methods of utilizing the UV curable toner compositions in various painting applications.

BACKGROUND

Disclosed herein are UV curable toner compositions and processesthereof. In the embodiments disclosed, the toner compositions providedherein can be selected for use in graphic arts and packagingapplications, such as more specifically, temperature sensitive packagingand foil seals.

A current trend in the printing industry is xerographic packagingapplications. Such applications generally utilize heat fused toners.However, there are a number of problems associated with using heat fusedtoners in these applications. One problem relates to printing ontemperature sensitive packaging or substrates. It would be desirable toprovide a toner composition that is fusible without significant heatingor heating at high temperatures.

Additionally, printing for a number of packaging applications canrequire the use of materials that are durable and which are resistant toa variety of conditions and environmental factors. Conventional packageprinting uses curable inks to “toughen” the resulting printed image orindicia such that the image or indicia on the final packaging is durableand wear-resistant. In addition, many offset printings use a heatedovercoat to protect the image from abrasion. However, overcoats appliedto fused and unfused images can cause degradation of image quality.Accordingly, there is a need for a toner composition that in embodimentsmay not require a protective overcoat.

Furthermore, in the graphic arts industry and for a number of otherentities, printing is performed on a wide array of substrates andsurfaces such as on yogurt containers, foil seals for containers andother diverse packaging configurations. There can be a number ofdisadvantages associated with using heat fused xerographic toners inthese traditionally lithographic printing applications. Manylithographic applications use an overcoat that is subsequently heated toprotect images from abrasion. However, applying overcoats to fused andunfused toner can disturb the toner piles. Overcoats are usually appliedwith heat and this heat causes dry toners to smear and possibly undergophase separation that can damage image quality. Accordingly, there isalso a need for a single application printing process that can avoid theneed for an overcoat, and particularly can avoid a multi-step processwhich includes a step of applying and heating an overcoat.

BRIEF DESCRIPTION

Disclosed herein is a method for providing a UV curable tonercomposition and the toner composition produced thereby. Also disclosedare methods of utilizing the UV curable toner compositions in printingprocesses to overcome one or more of the difficulties noted above.

Also disclosed herein are various toner emulsion aggregation processesthat permit the generation of toners that in embodiments can be cured,that is by the exposure to UV radiation, such as UV light of has about100 nm to about 400 nm. In the embodiments disclosed, the tonercompositions produced can be utilized in various printing applicationssuch as temperature sensitive packaging and the production of foilseals.

Aspects disclosed herein in the embodiments relate to a UV curable tonercomposition comprised of an optional colorant, an optional wax, apolymer generated from styrene, and acrylate selected from the groupconsisting of butyl acrylate, carboxyethyl acrylate, and a UV lightcurable acrylate oligomer.

Additionally, these aspects relate to a toner composition comprised of acolorant such as a pigment, an optional wax, and a polymer generatedfrom a UV curable cycloaliphatic epoxide.

Furthermore, these aspects relate to a method of forming a UV curabletoner composition. The method comprises preparing a latex of a polymerformed from styrene, butyl acrylate, 2-carboxymethyl acrylate, and a UVcurable acrylate; combining the latex with an optional pigment and anoptional wax to form a first system; adding flocculant to the firstsystem to induce aggregation and form toner precursor particlesdispersed in a second system; heating the toner precursor particles to atemperature greater than the glass transition temperature of the polymerto form toner particles; washing the toner particles; and optionallywashing and then drying the toner particles.

Moreover, these aspects relate to a method of forming a UV curable tonercomposition comprising mixing a latex containing a polymer formed fromstyrene, butyl acrylate, a carboxymethyl acrylate, and a UV curableacrylate with a colorant and wax; adding flocculant to this mixture tooptionally induce aggregation and form toner precursor particlesdispersed in a second mixture; heating the toner precursor particles toa temperature equal to or higher than the glass transition temperature(T_(g)) of the polymer to form toner particles; optionally washing thetoner particles; and optionally drying the toner particles. A furtheraspect relates to the toner particles produced by this method.

These aspects also relate to a method of forming a UV curable tonercomposition, the method comprising mixing a latex of a polymer formedfrom styrene, butyl acrylate, and carboxymethyl acrylate, with pigmentand wax to form a first system; adding flocculant to the first system toinduce aggregation and form toner precursor particles dispersed in asecond system; adding a UV curable acrylate to the second system to forma shell on the toner precursor particles; heating the toner precursorparticles to a temperature greater than the glass transition temperatureT_(g) of the shell to form toner particles; and, optionally washing anddrying the toner particles. The resulting toner particles produced bythis method are also included herein.

One advantage of the present exemplary embodiment is the provision of aUV curable toner composition that does not require an overcoatsubsequently applied onto the toner.

Another advantage of the present exemplary embodiment is the provisionof a toner composition that does not require heat for fusing. Thiscomposition will find wide applications in printing of temperaturesensitive packaging or substrates.

Still further advantages and benefits of the present exemplaryembodiment will become apparent to those of ordinary skill in the artupon reading and understanding the following detailed description of thepreferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary embodiment may take form in various components andarrangements of components, and in various steps and arrangements ofsteps. The drawings are only for purposes of illustrating preferredembodiments and are not to be construed as limiting the exemplaryembodiment.

FIG. 1 is a schematic flow chart depicting a process for forming apreferred embodiment emulsion aggregation particles.

FIG. 2 is a schematic flow chart illustrating another process of formingpreferred embodiment emulsion aggregation particles.

DETAILED DESCRIPTION

Emulsion aggregation toners are provided that are curable upon exposureto ultraviolet light. These toners are generally referred to herein as“UV curable EA toners.” As will be appreciated by those skilled in theart, the designation “EA” refers to emulsion aggregation. And “UV”refers to ultra-violet light, that is light having a wavelength of fromabout 100 nm to about 400 nm. The toners described herein can beobtained by incorporating into the toner particles during theirformation, acrylate oligomers containing ethylenically unsaturatedsites. UV curing of the resulting toner composition is then utilized tocreate very durable and wear resistant images for packaging and otherapplications. A UV-active EA latex incorporating styrene-butylacrylate-2-carboxyethyl acrylate-polyurethane oligomer is also provided.Additionally, a UV curable lacquer is incorporated into EA tonerparticles in the aggregation process in order to enable post-fusing UVcuring of the toner. This strategy provides the functionality of alacquer coating in a one-step process. This is important for packagingapplications to improve image durability.

The preferred toner compositions are based upon copolymer resins ofstyrene, butyl acrylate, and 2-carboxyethyl acrylate. A 2-carboxyethylacrylate-containing resin may be used and is ideal for furthercrosslinking after printing via UV light radiation. The EA tonersdescribed herein are ideal for packaging printing because of theversatile resin design and toner morphology.

It is instructive to consider EA technology. For example,emulsion/aggregation/coalescing processes for the preparation of tonersare illustrated in a number of patents, the disclosures of which aretotally incorporated herein by reference, such as U.S. Pat. No.5,290,654, U.S. Pat. No. 5,278,020, U.S. Pat. No. 5,308,734, U.S. Pat.No. 5,370,963, U.S. Pat. No. 5,344,738, U.S. Pat. No. 5,403,693, U.S.Pat. No. 5,418,108, U.S. Pat. No. 5,364,729, and U.S. Pat. No.5,346,797; and also of interest may be U.S. Pat. Nos. 5,348,832;5,405,728; 5,366,841; 5,482,812; 5,496,676; 5,527,658; 5,585,215;5,622,806; 5,650,255; 5,650,256 and 5,501,935; 5,723,253; 5,744,520;5,763,133; 5,766,818; 5,747,215; 5,827,633; 5,853,944; 5,804,349;5,840,462; 5,869,215; 5,863,698; 5,902,710; 5,910,387; 5,916,725;5,919,595; 5,922,501; 5,925,488; 5,945,245; and 5,977,210. Thecomponents and processes of the patents can be selected for the presentdevelopment and embodiments thereof.

More specifically, the present development provides an EA tonercomprising styrene, butyl acrylate, 2-carboxyethyl acrylate, and UVlight curable acrylate oligomer. The composition optionally alsoincludes an effective amount of a photoinitiator, which upon beingexposed to ultraviolet light, causes the EA toner to substantiallyimmediately polymerize. The UV light curable acrylate oligomer ispresent in the EA toner composition in an amount of from 1 to about 15percent by weight, and preferably in an amount of from about 2 to about10 percent by weight. When a photoinitiator is employed in the EA tonercomposition, it is generally used in an amount of from about 0.1 toabout 5 weight percent of the EA toner, and preferably from about 0.5 toabout 2 percent by weight

Any suitable UV light curable acrylate oligomeric material that iscompatible with the monomers of (i) styrene, (ii) butyl acrylate, and2-carboxyethyl acrylate can be employed so long as the oligomer containsethylenically unsaturated sites that will react with the unsaturatedgroups present in the monomers (i) and (ii) set forth above. Suitablematerials include end-capped acrylate moieties present on such oligomersas epoxy-acrylates, polyester-acrylates, acrylate oligomers, polyetheracrylates, polyether-urethane acrylates, polyester-urethane acrylates,and the like. Polyurethanes, end-capped with acrylate moieties such ashydroxyethyl acrylate are preferred. Further, the polyurethane oligomercan be prepared utilizing an aliphatic diisocyanate such ashexamethylene diisocyanate, cyclohexane diisocyanate,diisocyclohexylmethane diisocyanate, isophorone diisocyanate, and thelike. Isophorone diisocyanate can be used. Another example is apolyester polyurethane prepared from adipic acid and neopentyl glycol.The polyester together with a further quantity of neopentyl glycol isreacted with an excess of isophorone diisocyanate and then theisocyanate groups on the terminal portion of the molecule are reactedwith hydroxyl ethyl acrylate. An example of a suitable material is onesold under the grade designation CN966-H90 by Sartomer Company.

Table 1 illustrate several examples of UV curable acrylate copolymersfrom Sartomer Company. After curing by exposure to UV light, thecopolymers are toughened and provide excellent gloss and waterresistance, which is one of the important requirements for mostpackaging applications. In contrast, conventional EA toner is verysensitive to water and relative humidity. TABLE 1 Examples of UV CurableAcrylate Copolymers Viscosity MW (cps) Oligomer Backbone M = 1,000 @ 60°C. Group I CN964 Ester 1.6-1.8M 21,000 CN966 Ester 5.4-5.6M 70,000 GroupII CN981 Ester/Ether — 10,000 CN982 Ester/Ether 1.6-1.8M 9,375 Group IIICN986 Ether 1.6-1.8M 450 Pro1154 Ether 5.4-5.6M 26,500 CN301 Butadiene —4,175

Representative properties for several of these UV curable acrylates areset forth below in Tables 2-4. CN964 is an aliphatic polyester basedurethane diacrylate oligomer. CN981 is an aliphatic polyester/polyetherbased urethane diacrylate oligomer. CN301 is a polybutadienedimethyacrylate. TABLE 2 CN964 TYPICAL PHYSICAL AND CHEMICAL PROPERTIESAppearance Clear liquid Color, APHA 30 Density, lbs./gal. 9.185Elongation, % 49 Functionality 2 Modulus, psi. @ % 7679 Molecular Weight3710 Refractive index 25′ 1.4848 Tensile Strength, psi. 1001 T_(g), ° C.−24 Viscosity @ 60′c cps 17,675

TABLE 3 CN-981 TYPICAL PHYSICAL AND CHEMICAL PROPERTIES Functionality 2Appearance Clear liquid Inhibitor, ppm. <400 MEHQ Color, APHA (G =Gardner 65 scale) Density, lbs./gal. 9.308 Viscosity, cps. 6190 @ 60° C.Refractive Index 1.4908 T_(g), ° C. 22 Tensile Strength, psi. 1113Elongation, % 81 Modulus, psi. @ 1% 6385

TABLE 4 CN301 TYPICAL PHYSICAL AND CHEMICAL PROPERTIES Acid value, mgkoh/g <5 Color, APHA 9G Density, lbs./gal. 8.045 Elongation 25Functionality 2 Refractive index 25′ 1.5072 Tensile Strength, psi. 505T_(g), C. −75 Viscosity, cps. @ 40° C. 890 @ 60° C.

Additional examples of commercially available UV curable monomers thatcan be used in the embodiments herein, include but are not limited to,tris (2-hydroxy ethyl) isocyanurate triacrylate (SR 368 Sartomer) fromAtofina; ethoxylated pentaerythritol tetraacrylate (Sartomer SR 494)from Atofina; pentaerythritol tetracrylate (Sartomer SR 295);dipentaerythritol pantaacrylate (Sartomer SR 399); chlorinated polyesteracrylate (Sartomer CN 2100) from Atofina; amine modified epoxy acrylate(Sartomer CN 2100); aromatic urethane acrylate (Sartomer CN 2901);polyurethane acrylate laromer LR 8949 from BASF; aromatic urethanetriacrylate CN 970 from Atofina; aliphatic diacrylate oligomer CN 132from Atofina; aliphatic urethane diacrylate CN 981 from Atofina; andaromatic urethane diacrylate CN976 from Atofina.

Suitable photoinitiators may be employed in the toner compositionsdescribed herein such as 2-hydroxy-2-methyl-1-phenyl-1-propanoneavailable from Ciba-Geigy under the grade designation Darocur 1173;1-hydroxycyclohexylphenyl ketone;2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one;2,2-dimethoxy-2-phenylacetophe morpholinyl)-1-propanone available fromCiba-Geigy under the grade designation Irgacure® 184, 369, 651, and 907respectively.

Additional examples of commercially available photoinitiators fromCiba-Specialty Chemicals, include, but are not limited to,2-hydroxy-2-methyl-1-phenyl-propan-1-one (HMPP)—Darocure 1173;2,4,6-trimethyl benzoyl diphenyl phosphine oxide (TPO)—Darocure 4265;50-50 Blend of HMPP and TPO; 2-methyl-1[4-(methylthio)phenyl]-2-morpholino propan-1one (MMMP)—Irgacure 907; and2,2-dimethoxy-2-phenyl acetophenone (BDK)—Irgacure 651. Examples ofcommercially available photoinitiators from BASF, include, but are notlimited to, 2,4,6-trimethyl benzoyl diphenyl phosphine oxide (LucirinTPO); alpha hydroxyketone; and 2-hydroxy-2-methyl-phenyl-1-propane.

Also provided is a UV-active EA latex incorporating styrene-butylacrylate-2-carboxyethyl acrylate-polyurethane oligomer. EA styrene-butylacrylate-2-carboxyethyl acrylate-polyurethane oligomer latex can beprepared via a semi-continuous emulsion polymerization process. FIG. 1illustrates a process for forming EA toner. The UV curable latex isreadily incorporated into the process. The UV curable latex can be addedat the beginning of the aggregation process, i.e. prior to aggregationof the toner particles, or it can be introduced as the “shell” latex inthe middle of the aggregation stage. UV curable EA toner particles areformed by making a physical mixture of latex, pigment, wax,photoinitiator, and/or silica at the primary particle size, andinitiating aggregation with a cationic flocculant. Following thecoalescence step at a temperature higher than the resin glass transitiontemperature (T_(g)), the resulting particles are washed and dried.

More specifically, a process for forming the UV curable EA tonerdescribed herein can involve combining styrene, butyl acrylate, and2-carboxyethyl acrylate with pigment and wax. As previously noted, theUV curable acrylate oligomer may be added at this point in the processor later in the process, i.e. at the beginning of the aggregation stepto form a shell. After a suitable mixture or dispersion is formed,aggregation is initiated by addition of a cationic flocculant. This isgenerally followed by mixing and heating operations. The resultingsystem and toner particles are then heated to a temperature that isgreater than the T_(g) of the polymer or shell component of the toner.The resulting particles are then washed. One or more suitable dryingoperations are then performed on the toner particles.

A typical UV light curing process for the embodiment EA toners is asfollows. After the fusing step, the EA toner image is exposed to a cureunit such as a Linde PS-2000 UV system, with UV lamps generating 2×400watts/in.² The cure rates can be from about 10 to about 300 feet perminute on a typical substrate.

A significant advantage of employing UV light curing of EA toners isthat the post-crosslinking may be performed by utilizing the chemicalfunctional group incorporated in the EA toner resin.

When utilizing the EA toner compositions described herein on packagingthat is heat treated or otherwise subjected to a heating operation, i.e.food packaging, it is important that the images on the printed packagingnot be altered by the application of heat. That is, the deposited tonershould not flow under heat once fused to the substrate. A strategy forpreventing fused toner flow involves exposure of the toner compositionto UV radiation to thereby cause crosslinking of the toner resin.

The embodiment UV curable toner compositions have numerous applications.The various compositions described herein enable better fusing of tonerson rough stock. Many xerographic toners exhibit difficulty with fusingon thick or rough papers. It is difficult to transfer the heat of aheat-roll fuser system through heavy and textured papers, and even moredifficult to transfer the heat to the very high surface area of colorimages. Additionally, the embodiments may be used in conjunction with awide variety of existing technologies. For example, a conventionalprinting operation may provide a tough and durable image or indicia byutilizing the EA toner and curing by subsequent exposure to UV light. Aheat-roll fuser is utilized to initially fuse the printed image orindicia. That operation is followed by exposure to a low temperature, UVcure unit that can initiate the UV curing of a fused EA toner image. Thecuring operation helps bond the image to itself and the paper, andthereby improves the copy quality metrics of crease and rub. Further, UVcured images will perform better in recirculating document handlers. UVcurable toner will further promote consumer satisfaction.

In another aspect, a UV curable lacquer component is incorporated intoan EA particle. As will be understood by those skilled in the art, alacquer coating is a coating formulated with an acrylic resin that driesto provide a solid, protective film. The term “UV curable lacquercomponent” refers to any UV curable acrylic resin.

The styrene acrylate EA particles are formed by making a physicalmixture of anionic components (latex, pigment, wax, silica, etc.) attheir primary particle size, and initiating aggregation with a cationicflocculant. In a styrene acrylate system, a shell of latex is added tothe aggregated particle during the coalescence step. This process isdepicted in FIG. 2. Referring to FIG. 2, that figure illustrates aprocess including steps A through F for forming EA toner. Step A is ahomogenization step for blending the various components. Thesecomponents include a latex which, for example, may be a styrene-butylacrylate, 2-carboxyethyl acrylate copolymer for fusing and chargingcontrol. Additionally, another component added during Step A includesthe desired pigments. Furthermore, the components in Step A may includewax and also internal colloidal silica. Step B is an aggregation step inwhich the particles are formed to a desired size. A flocculant such aspolyaluminum chloride may be used. Mixing and heating operations aretypically employed in Step B. Step C is the shell addition step in whichpigment is retained inside the resulting particle. Effective amounts ofsodium hydroxide may be added for particle stabilization. In Step D, acoalescence operation occurs. This assists in melting the latex tocontrol particle shape and also control surface properties. Generallymixing and heating are performed during Step D. Nitric acid may be addedto assist in shape and surface control. In Step E, a washing operationis performed to remove surfactants. Additional sodium hydroxide may beadded for removal of surfactants. And additional nitric acid may beadded for base neutralization. In Step F, a drying operation isperformed. This serves to control moisture and pH.

In accordance with this methodology, a strategy is to incorporate a UVcurable resin as the lacquer component, as a shell to the EA particle,where a photoinitiator is included in the body of the particle. Due toits cationic nature, this photoinitiator could be used as a flocculantin the aggregation process.

It will be appreciated that the toner embodiments described hereininclude toner particles in which the UV curable component is locatedwithin specific regions of a toner particle. For example, an EA toner isprovided in which the UV curable resin and photoinitiator isincorporated into the shell. An EA toner is also provided in which theUV curable component is incorporated into the toner core, while theother component(s) are incorporated into the toner shell. An EA toner isprovided in which the UV curable components are blended on the surfaceof the toner as external additives. And, an EA toner is provided inwhich one UV curable component is incorporated into the interior of thetoner while one or more additional UV curable components are blended onthe surface of the toner.

Furthermore, it will be understood that the various emulsion aggregationprocesses described herein include embodiments that involve mixingpolymeric resin, UV curable component and optionally pigment, wax andphotoinitiator and aggregating them to form UV curable EA toner. Theembodiments also involve dispersing a UV curable component along withtoner latex prior to the aggregation process and then aggregating theresulting system to form toner particles. Additionally, the embodimentsinvolve dispersing both the UV curable component and photoinitiatoralong with latex prior to the aggregation process such that they areaggregated together with other toner components such as pigment, wax,etc. Moreover, the embodiments involve preparation of the previouslynoted toner in which the aggregation is performed with or without UVcurable materials (UV curable resin and optionally photoinitiator) andthe UV curable resin and optionally photoinitiator are added with theshell, or as the shell, after the aggregation and before thecoalescence. And, the embodiments involve adding the UV curablecomponent and potentially the photoinitiator as powders during theadditive blending process.

The mechanism for the lacquer curing process is a two phase process. Ina first step, i.e. the fusing step, the shell resin is crushed andallowed to come into physical contact with the photoinitiator material.After the fusing step, the image is exposed to a Cure Unit such as thepreviously noted Linde PS-2000, with UV lamps producing 2×400watts/inch. The cure rates of the proposed resin-photoinitiator systemwould be about 300 to about 500 feet per minute on a typical substrate.

Preferred UV curable resins for use as the lacquer component in theembodiment systems include, but are not limited to, UV cycloaliphaticepoxides. Representative cycloaliphatic epoxides include, but are notlimited to 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylateand bis-(3,4-3poxycyclohexyl) adipate. An example of a commerciallyavailable system is Cyracure®, which is currently available from UnionCarbide Corporation. Cyracure® is a low viscosity epoxide resin, whichis used in conjunction with a Cyracure® photoinitiator, which is acationic salt such as mixed triarylsulfonium hexafluoroantimonate saltsor mixed triarylsulfonium hexafluorophosphate salts. This cationic UVcurable lacquer formulation has shown excellent results in the type ofapplications generally associated with EA toner compositions. Thecationic UV curable lacquer formulation functions as an overprintvarnish (OPV) on both tin-free steel and aluminum for rigid packaging,and as a paper coating and as a plastic substrate coating. The curedlacquers provide retortable and pasteurizable films exhibitingnoteworthy adhesion, flexibility and protective properties.

Representative components of the Cyracure® system include, but are notlimited to those set forth in Table 5, below. TABLE 5 RepresentativeComponents of the Cyracure ® System CYRACURE ® Products DescriptionFunction Resins UVR-6105 Low-viscosity base Contributes primary filmepoxide resin properties UVR-6110 Base epoxides resin Contributesprimary film properties UVR-6128 Flexible epoxides Contributes primaryfilm resin properties Diluents UVR-6000 Oxetane dilutent Viscosityreducer UVR-6100 Cycloaliphatic Viscosity reducer epoxides diluentUVR-6216 Linear aliphatic Viscosity reducer diluent PhotoinitiatorsUVI-6976 Aryl sulfonium salt For fastest cure speeds and/or thick orpigmented films UVI-6992 Aryl sulfonium salt For most thin films (<1mil) applications

The chemical structures of the resins and photoinitiators in Table 5 areas follows:

Tables 6, 7, and 8 describe typical properties of the Cyracure® resins,diluents, and photoinitiators: TABLE 6 Typical Properties of Cyracure ®Resins Product UVR-6105 UVR-6110 UVR-6128 Chemical Name 3,4 3,4-Bis-(3,4- Epoxycyclohexylmethyl- Epoxycyclohexylmethyl epoxycyclohexyl)3,4- 3,4- Adipate Epoxycyclohexane Epoxycyclohexane CarboxylateCarboxylate- Epoxide Equivalent Weight 130-135 131-143 190-210 Viscosityat 25° C., cP 220-250 350-450 550-750 Specific Gravity at 20/20° C. 1.161.173 1.149 Vapor Pressure at 20° C., <0.01 Nil Nil mm Hg Color, Pt-Co<50 <100 <100 Primary Irritation Index Skin, Draize Value (0-8) 1.6 1.350.25 Eye, Draize Value (0-110) 8.0 7.5 4.0

TABLE 7 Typical Properties of Cyracure ® Diluents Product UVR-6000UVR-6216 UVR-6100 Chemical Name 3-Ethyl-3- 1,2- Mixed hydroxy- Epoxy-cycloaliphatic methyl- hexadecane epoxides oxetane Equivalent Weight c.116 240-280 130-140 Viscosity at 25° C., cP c. 22 <15  85-115 SpecificGravity at 20/20° 1.04 0.844 1.1395 Vapor Pressure at 20° C., — <0.010.59 mm Hg Color, Pt-Co — <50 <100 Primary Irritation Index Skin, DraizeValue (0-8) — 3.8 0.9 Eye, Draize Value (0-110) — 4.0 1.0

TABLE 8 Typical Properties of Cyracure ® Photoinitiators ProductUVR-6976 UVR-6992 Chemical Name Mixed Mixed TriarylsulfoniumTriarylsulfonium Hexafluoroantimonate Hexafluorophosphate Salts SaltsDescription Cationic Cationic Photoinitiator Photoinitiator AntimonateSalt Phosphate Salt Faster curing than UVI-6992 Viscosity at 25° C., cP75 75 Specific Gravity at 1.39 1.32 25/25° Vapor Pressure at 20° C.,<0.03 <0.03 mm Hg Color, Gardner Scale 5 5

It will be appreciated that the properties of the Cyracure® may beadjusted as desired. For example, if greater flexibility of theresulting composition is desired, various polyols available under thedesignation Cyracure® Tone® may be added to the composition prior tocuring.

UV curable lacquer and toner compositions provide numerous benefits fora wide array of applications. UV curable lacquers enable better fusing,i.e. improved durability and wear resistance, of toners on rough stock.All xerographic toners struggle with fusing on thick or rough papers. Itis difficult to transfer the heat of a heat-roll fuser system throughheavy and textured papers, much less the very high area coverage ofcolor images. A low viscosity epoxy can flow to the paper and improvethe quality and overall aesthetics of crease and rub. Further, UV curedimages will perform better in recirculating document handlers. UVcurable toner can be a significant customer satisfier.

The various embodiment toner compositions can be applied on a wide arrayof substrates. For example, the substrate may be paper, cardboard,plastic, foil, metal, and combinations thereof.

Printing and/or coating processes can use the various embodiment tonercompositions. Generally, a substrate as previously noted is provided. Atoner composition is also provided. Generally, the toner composition isone including a polymer generated from styrene and acrylate selectedfrom the group consisting of butyl acrylate, carboxyethyl acrylate, anda UV light curable acrylate oligomer and optionally a colorant.Alternately, the toner composition can be one that includes a polymergenerated from a UV curable cycloaliphatic epoxide and a colorant. Thetoner composition is applied onto the substrate using known coating orprinting techniques. The toner composition is then cured by exposure toUV light.

Several trials were conducted to evaluate the characteristics of a UVcurable toner composition as described herein.

Specifically, three EA toner compositions were prepared. These wereyellow EA toners prepared with UV curable resins in an emulsionpolymerization step, then aggregated with pigment and wax to form UVcurable EA toners. These UV curable monomers/oligomers in EA latexpreparation were: (1) polyesterurethane acrylate; (2) dimethylm-isopropenyl benzyl isocyanate; and (3) trimethylolpropane triacrylate.The yellow EA toners were evaluated by forming images in a MajectiK 5765copier in Xerox 4024 paper, and fusing the image using an Imari-MF freebelt nip fuser. After the fusing step, the EA toner images were exposedto a UV curing system, with an energy of about 14 joule/cm², and lightwavelength of about 150 to 375 nm. The radiation temperature wasmaintained between 25 to 30° C. The post-cured EA toner imagesdemonstrated excellent rub resistance. The images resisted 40 doublerubs with a toluene laden cloth.

Additional examples of polymer latex synthesis and toner particlepreparation are as follows.

POLYMER LATEX SYNTHESIS Latex Example (I). Poly(styrene-butylacrylate-acrylic acid-β-carboxyethyl acrylate) Polymer Latex

A polymer latex (EP406) comprised of a styrene/n-butylacrylate/β-carboxyethyl acrylate copolymer of 74:23:3 prepared with 1.7pph dodecanethiol (chain transfer agent), 0.35 pph branching agent(A-DOD, decanediol diacrylate, available from Shin-Najamura Co., Japan)and 1.5 percent of ammonium persulfate initiator was synthesized by asemicontinuous emulsion polymerization process using the anionicsurfactant DOWFAX 2A1™ (sodium tetrapropyl diphenoxide disulfonate, 47percent active, available from Dow Chemical).

In a 3 gallon jacketed stainless steel reactor with double flightimpellers (a four pitched-blade impeller each) set at 35 rpm, 3.87kilograms of deionized water with 5.21 grams of DOWFAX 2A1™ (7 percentof the total surfactant) were charged while the temperature was raisedfrom room, about 23 to about 25° C. to 75° C. A monomer emulsion wasprepared by mixing a monomer mixture (3108 grams of styrene, 966 gramsof n-butyl acrylate, 122 grams of 2-carboxyethyl acrylate (β-CEA)), 14.3grams of A-DOD and 45 grams of 1-dodecanethiol with 1930 grams ofdeionized water and 80.7 grams of DOWFAX 2A1™ (93 percent of the totalsurfactant) at room temperature for 30 minutes in a 1.5 gallon Popetank. 63 grams of the seed were pumped from the monomer emulsion into a0.2 gallon beaker and subsequently the seed was charged into the reactorat 75° C. An initiator solution prepared from 61 grams of ammoniumpersulfate in 302 grams of deionized water was added over 20 minutesafter the seed emulsion addition. The reactor was stirred at 48 rpm foran additional 20 minutes to allow seed particle formation at 75° C. Themonomer emulsion was then fed into the reactor. Monomer emulsion feedingwas stopped after 110 minutes and 24.9 grams of 1-dodecanethiol (DDT)were added to the remaining emulsion in the 1.5 gallon Pope tank whichwas mixed for a further 5 minutes before feeding resumed. The remainingmonomer emulsion was fed into the reactor over 90 minutes. At the end ofthe monomer feed, the emulsion was post-heated at 75° C. for 180minutes, then cooled to 25° C. The reaction system was deoxygenated bypassing a stream of nitrogen through it during the reaction. A latexresin containing 42 weight percent styrene-butyl acrylate-β-carboxyethylacrylate resin, 57 weight percent water, 0.4 weight percent anionicsurfactant Dowfax 2A1™, 0.6 percent of an ammonium sulfate salt specieswas obtained. The resulting amorphous polymer poly(styrene-butylacrylate-acrylic acid-β-carboxyethyl acrylate) possessed aweight-average molecular weight M_(w) of 33,200, and a number-averagemolecular weight M_(n) of 10,400, as determined on a Waters GPC, and amid-point Tg of 50.7° C., as measured on a Seiko DSC. The latex resin orpolymer possessed a volume average diameter of 222 nanometers asmeasured by light scattering technique on a Coulter N4 Plus ParticleSizer.

Latex Example (II). Poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-urethane acrylate) Polymer Latex

A polymer latex (EP432) comprised of a styrene/n-butylacrylate/β-carboxyethyl acrylate/urethane acrylate copolymer of70:19:3:8 prepared with 1.7 pph dodecanethiol (chain transfer agent),0.35 pph branching agent (A-DOD, decanediol diacrylate) and 1.5 percentof ammonium persulfate initiator was synthesized by a semicontinuousemulsion polymerization process using the anionic surfactant DOWFAX2A1™. The UV curable urethane acrylate oligomer is available fromSartomer Co. under the grade designation CN966-H90.

In a 3 gallon jacketed stainless steel reactor with double flightimpellers (a four pitched-blade impeller each) set at 35 rpm, 3.87kilograms of deionized water with 5.21 grams of DOWFAX 2A1™ (7 percentof the total surfactant) were charged while the temperature was raisedfrom room, about 23 to about 25° C. to 75° C. A monomer emulsion wasprepared by mixing a monomer mixture (2937 grams of styrene, 797 gramsof n-butyl acrylate, 126 grams of 2-carboxyethyl acrylate (β-CEA)), 336grams of urethane acrylate oligomer (CN966-H90), 16.8 grams of2-hydroxy-2-methyl-1-phenyl-1-propane (photoinitiator, available fromCiba-Geigy under the grade designation Darocur 1173), 14.3 grams ofA-DOD and 45 grams of 1-dodecanethiol with 1930 grams of deionized waterand 80.7 grams of DOWFAX 2A1™ (93 percent of the total surfactant) atroom temperature for 30 minutes in a 1.5 gallon Pope tank. 63 grams ofthe seed were pumped from the monomer emulsion into a 0.2 gallon beakerand subsequently the seed was charged into the reactor at 75° C. Aninitiator solution prepared from 61 grams of ammonium persulfate in 302grams of deionized water was added over 20 minutes after the seedemulsion addition. The reactor was stirred at 48 rpm for an additional20 minutes to allow seed particle formation at 75° C. The monomeremulsion was then fed into the reactor. Monomer emulsion feeding wasstopped after 110 minutes and 24.9 grams of 1-dodecanethiol (DDT) wereadded to the remaining emulsion in the 1.5 gallon Pope tank which wasmixed for a further 5 minutes before feeding resumed. The remainingmonomer emulsion was fed into the reactor over 90 minutes. At the end ofthe monomer feed, the emulsion was post-heated at 75° C. for 180minutes, then cooled to 25° C. The reaction system was deoxygenated bypassing a stream of nitrogen through it during the reaction. A latexresin containing 42 weight percent styrene-butyl acrylate-β-carboxyethylacrylate-urethane acrylate resin, 57 weight percent water, 0.4weight percent anionic surfactant Dowfax 2A1™, 0.6 percent of anammonium sulfate salt species was obtained. The resulting amorphouspolymer poly(styrene-butyl acrylate-acrylic acid-β-carboxyethylacrylate-urethane acrylate) possessed a weight-average molecular weightM_(w) of 37,100, and a number-average molecular weight M_(n) of 11,600,as determined on a Waters GPC, and a mid-point Tg of 51.2° C., asmeasured on a Seiko DSC. The latex resin or polymer possessed a volumeaverage diameter of 241 nanometers as measured by light scatteringtechnique on a Coulter N4 Plus Particle Sizer.

Latex Example (III). Poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-dimethyl m-isopropenyl benzyl isocyanate)Polymer Latex

A polymer latex (EP443) comprised of a styrene/n-butylacrylate/β-carboxyethyl acrylate/dimethyl m-isopropenyl benzylisocyanate copolymer of 71:20:3:6 prepared with 1.7 pph dodecanethiol(chain transfer agent), 0.35 pph branching agent (A-DOD, decanedioldiacrylate) and 1.5 percent of ammonium persulfate initiator wassynthesized by a semicontinuous emulsion polymerization process usingthe anionic surfactant DOWFAX 2A1™. UV curable dimethyl m-isopropenylbenzyl isocyanate is available from Cytec Industries under the tradename TMI.

In a 3 gallon jacketed stainless steel reactor with double flightimpellers (a four pitched-blade impeller each) set at 35 rpm, 3.87kilograms of deionized water with 5.21 grams of DOWFAX 2A1™ (7 percentof the total surfactant) were charged while the temperature was raisedfrom room, about 23 to about 25° C. to 75° C. A monomer emulsion wasprepared by mixing a monomer mixture (2979 grams of styrene, 839 gramsof n-butyl acrylate, 126 grams of 2-carboxyethyl acrylate (β-CEA)), 252grams of dimethyl m-isopropenyl benzyl isocyanate (TMI), 12.6 grams of2-hydroxy-2-methyl-1-phenyl-1-propane (photoinitiator, available fromCiba-Geigy under the grade designation Darocur 1173), 14.3 grams ofA-DOD and 45 grams of 1-dodecanethiol with 1930 grams of deionized waterand 80.7 grams of DOWFAX 2A1™ (93 percent of the total surfactant) atroom temperature for 30 minutes in a 1.5 gallon Pope tank. 63 grams ofthe seed were pumped from the monomer emulsion into a 0.2 gallon beakerand subsequently the seed was charged into the reactor at 75° C. Aninitiator solution prepared from 61 grams of ammonium persulfate in 302grams of deionized water was added over 20 minutes after the seedemulsion addition. The reactor was stirred at 48 rpm for an additional20 minutes to allow seed particle formation at 75° C. The monomeremulsion was then fed into the reactor. Monomer emulsion feeding wasstopped after 110 minutes and 24.9 grams of 1-dodecanethiol (DDT) wereadded to the remaining emulsion in the 1.5 gallon Pope tank which wasmixed for a further 5 minutes before feeding resumed. The remainingmonomer emulsion was fed into the reactor over 90 minutes. At the end ofthe monomer feed, the emulsion was post-heated at 75° C. for 180minutes, then cooled to 25° C. The reaction system was deoxygenated bypassing a stream of nitrogen through it during the reaction. A latexresin containing 42 weight percent styrene-butyl acrylate-β-carboxyethylacrylate-dimethyl m-isopropenyl benzyl isocyanate resin, 57 weightpercent water, 0.4 weight percent anionic surfactant Dowfax 2A1™, 0.6percent of an ammonium sulfate salt species was obtained. The resultingamorphous polymer poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-dimethyl m-isopropenyl benzyl isocyanate)possessed a weight-average molecular weight M_(w) of 35,500, and anumber-average molecular weight M_(n) of 10,900, as determined on aWaters GPC, and a mid-point Tg of 52.1° C., as measured on a Seiko DSC.The latex resin or polymer possessed a volume average diameter of 233nanometers as measured by light scattering technique on a Coulter N4Plus Particle Sizer.

Latex Example (IV). Poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-trimethylolpropane triacrylate) PolymerLatex

A polymer latex (EP444) comprised of a styrene/n-butylacrylate/β-carboxyethyl acrylate/trimethylolpropane triacrylatecopolymer of 71:20:3:6 prepared with 1.7 pph dodecanethiol (chaintransfer agent), 0.35 pph branching agent (A-DOD, decanediol diacrylate)and 1.5 percent of ammonium persulfate initiator was synthesized by asemicontinuous emulsion polymerization process using the anionicsurfactant DOWFAX 2A1™. UV curable trimethylolpropane triacrylate isavailable from Sartomer Co. under the trade name SR351.

In a 3 gallon jacketed stainless steel reactor with double flightimpellers (a four pitched-blade impeller each) set at 35 rpm, 3.87kilograms of deionized water with 5.21 grams of DOWFAX 2A1™ (7 percentof the total surfactant) were charged while the temperature was raisedfrom room, about 23 to about 25° C. to 75° C. A monomer emulsion wasprepared by mixing a monomer mixture (2979 grams of styrene, 839 gramsof n-butyl acrylate, 126 grams of 2-carboxyethyl acrylate (β-CEA)), 252grams of trimethylolpropane triacrylate (SR351), 12.6 grams of2-hydroxy-2-methyl-1-phenyl-1-propane (photoinitiator, available fromCiba-Geigy under the grade designation Darocur 1173), 14.3 grams ofA-DOD and 45 grams of 1-dodecanethiol with 1930 grams of deionized waterand 80.7 grams of DOWFAX 2A1™ (93 percent of the total surfactant) atroom temperature for 30 minutes in a 1.5 gallon Pope tank. 63 Grams ofthe seed were pumped from the monomer emulsion into a 0.2 gallon beakerand subsequently the seed was charged into the reactor at 75° C. Aninitiator solution prepared from 61 grams of ammonium persulfate in 302grams of deionized water was added over 20 minutes after the seedemulsion addition. The reactor was stirred at 48 rpm for an additional20 minutes to allow seed particle formation at 75° C. The monomeremulsion was then fed into the reactor. Monomer emulsion feeding wasstopped after 110 minutes and 24.9 grams of 1-dodecanethiol (DDT) wereadded to the remaining emulsion in the 1.5 gallon Pope tank which wasmixed for a further 5 minutes before feeding resumed. The remainingmonomer emulsion was fed into the reactor over 90 minutes. At the end ofthe monomer feed, the emulsion was post-heated at 75° C. for 180minutes, then cooled to 25° C. The reaction system was deoxygenated bypassing a stream of nitrogen through it during the reaction. A latexresin containing 42 weight percent styrene-butyl acrylate-β-carboxyethylacrylate-trimethylolpropane triacrylate resin, 57 weight percentwater, 0.4 weight percent anionic surfactant Dowfax 2A1™, 0.6 percent ofan ammonium sulfate salt species was obtained. The resulting amorphouspolymer poly(styrene-butyl acrylate-acrylic acid-β-carboxyethylacrylate-trimethylolpropane triacrylate) possessed a weight-averagemolecular weight M_(w) of 35,500, and a number-average molecular weightM_(n) of 10,900, as determined on a Waters GPC, and a mid-point Tg of52.1° C., as measured on a Seiko DSC. The latex resin or polymerpossessed a volume average diameter of 233 nanometers as measured bylight scattering technique on a Coulter N4 Plus Particle Sizer.

TONER PARTICLE PREPARATION EXAMPLE I 5.6 Micron Yellow Toner ParticlesGenerated by PAC A/C Process

The poly(styrene-butyl acrylate-acrylic acid-β-carboxyethylacrylate-urethane acrylate) polymer latex of Latex Example (II) (EP432)above was utilized in an aggregation/coalescence (A/C) process toproduce 5.6 micron (volume average diameter) particles with a narrowsize distribution.

500 grams of deionized water was placed in a stainless steel beaker andhomogenized at 5,000 rpm, while there was added 300 grams of latexpoly(styrene-butyl acrylate-acrylic acid-β-carboxyethylacrylate-urethane acrylate) (EP432), 37.16 grams of the polyethylene waxPOLYWAX 725® dispersion (Mw of 725, 31 percent active, available fromBaker-Petrolite Company) followed by the addition of 38.3 grams of PY74y llow pigment dispersion (17 percent active, available from SunChemicals) diluted with 110 grams of deionized water. To the resultinghomogenized latex/pigment blend, 2.4 grams of 10 percent PAC(polyaluminum chloride obtained from Asada Company of Japan) solutiondiluted with 24 grams of 0.02N HNO₃ was added dropwise to cause aflocculation of the PY74 yellow pigment, 6 percent by weight, thePOLYWAX 725®, 9 percent by weight, the resin, 84.88 weight percent, and0.12 weight percent of the PAC. After the addition was complete,homogenization was continued for an additional 2 minutes to form acreamy blend with an average particle size by volume of 2.68 and with aGSDv of 1.21. The creamy blend was then transferred into a 2 liter glassreactor and stirred at 350 rpm, while being heated to about 52° C. toabout 53° C. Particle growth was monitored during heating. When theparticle size diameter of the solids by volume was equal to 5.44(GSDv=1.20), the pH of the slurry was adjusted. The slurry was comprisedof about 16 weight percent of toner and of about 84 weight percent ofwater. The toner was comprised of about 6 percent of PY74 yellowpigment, about 9 percent of POLYWAX 725®, about 0.2 weight percent ofPAC and about 84.8 percent by weight of the resin poly(styrene-butylacrylate-acrylic acid-β-carboxyethyl acrylate-urethane acrylate), andwherein the total amount of the toner components was about 100 percent.The pH was adjusted to 7.5 by the addition of a 2 percent NaOH solutionand the speed in the reactor was reduced to 200 rpm. After ½ hour ofstirring at 53° C., the temperature in the reactor was increased to 95°C. After 1 hour of heating at 95° C., the pH of the slurry was adjustedto 4.3 and the heating was continued for an additional 5 hours.Thereafter, the reactor contents were cooled down to about roomtemperature, throughout the Examples, about 23° C. to about 25° C. andwere discharged. A 16 percent solids slurry of 5.62 micron black tonerparticles with GSDv=1.19 was obtained. The resulting toner product wascomprised of about 6 percent of PY74 yellow pigment, about 9 percent ofPOLYWAX 725®, about 0.2 weight percent of PAC and about 84.8 percent byweight of the resin poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-urethane acrylate), and wherein the totalamount of the toner components was about 100 percent. The tonerparticles were then washed with deionized water five times and dried.

EXAMPLE II 5.6 Micron Y llow Toner Particl s Generated by PAC A/C Procss

The poly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate)polymer latex of Latex Example (I) (EP406) and poly(styrene-butylacrylate-acrylic acid-β-carboxyethyl acrylate-dimethyl m-isopropenylbenzyl isocyanate) polymer latex of Latex Example (III) (EP443) abovewere utilized in an aggregation/coalescence (A/C) process to produce 5.6micron (volume average diameter) particles with a narrow sizedistribution.

500 grams of deionized water was placed in a stainless steel beaker andhomogenized at 5,000 rpm, while there was added 200 grams of polymerlatex poly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate)(EP406), 37.16 grams of the polyethylene wax POLYWAX 725® dispersionfollowed by the addition of 38.3 grams of PY74 yellow pigment dispersion(17 percent active, available from Sun Chemicals) diluted with 110 gramsof deionized water. To the resulting homogenized latex/pigment blend,2.4 grams of 10 percent PAC (polyaluminum chloride) solution dilutedwith 24 grams of 0.02N HNO₃ was added dropwise to cause a flocculationof the PY74 yellow pigment, 8.37 percent by weight, the POLYWAX 725®,12.55 percent by weight, the resin poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate), 78.91 weight percent, and 0.17 weightpercent of the PAC. After the addition was complete, homogenization wascontinued for an additional 2 minutes to form a creamy blend with anaverage particle size by volume of 2.68 and with a GSDv of 1.21. Thecreamy blend was then transferred into a 2 liter glass reactor andstirred at 350 rpm, while being heated to about 52° C. to about 53° C.Particle growth was monitored during heating. When the particle sizediameter of the solids by volume was equal to 4.84 (GSDv=1.21), 100grams of polymer latex poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-dimethyl m-isopropenyl benzyl isocyanate)(EP443) was added into the slurry mixture in the glass reactor. Particlegrowth was continuously monitored during heating. When the particle sizediameter of the solids by volume was equal to 5.43 (GSDv=1.22), the pHof the slurry was adjusted. The slurry was comprised of about 16 weightpercent of toner and of about 84 weight percent of water. The toner wascomprised of about 6 percent of PY74 yellow pigment, about 9 percent ofPOLYWAX 725®, about 0.2 weight percent of PAC, about 56.5 percent byweight of the resin poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-urethane acrylate), and about 28.3 percentby weight of resin poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-dimethyl m-isopropenyl benzyl isocyanate).The total amount of the toner components was about 100 percent. The pHwas adjusted to 7.5 by the addition of a 2 percent NaOH solution and thespeed in the reactor was reduced to 200 rpm. After ½ hour of stirring at53° C., the temperature in the reactor was increased to 95° C. After 1hour of heating at 95° C., the pH of the slurry was adjusted to 4.3 andthe heating was continued for an additional 5 hours. Thereafter, thereactor contents were cooled down to about room temperature, throughoutthe Examples, about 23° C. to about 25° C. and were discharged. A 16percent solids slurry of 5.65 micron black toner particles withGSDv=1.22 was obtained. The resulting toner product was comprised ofabout 6 percent of PY74 yellow pigment, about 9 percent of POLYWAX 725®,about 0.2 weight percent of PAC, about 56.5 percent by weight of theresin poly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate),and about 28.3 percent by weight of the resin poly(styrene-butylacrylate-acrylic acid-β-carboxyethyl acrylate-dimethyl m-isopropenylbenzyl isocyanate), and wherein the total amount of the toner componentswas about 100 percent. The toner particles were then washed withdeionized water five times and dried.

EXAMPLE III 5.6 Micron Yellow Toner Particles Generated by PAC A/CProcess

The poly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate)polymer latex of Latex Example (I) (EP406) and poly(styrene-butylacrylate-acrylic acid-β-carboxyethyl acrylate-trimethylolpropanetriacrylate) polymer latex of Latex Example (IV) (EP444) above wereutilized in an aggregation/coalescence (A/C) process to produce 5.6micron (volume average diameter) particles with a narrow sizedistribution.

500 grams of deionized water was placed in a stainless steel beaker andhomogenized at 5,000 rpm, while there was added 200 grams of polymerlatex poly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate)(EP406), 37.16 grams of the polyethylene wax POLYWAX 725® dispersionfollowed by the addition of 38.3 grams of PY74 yellow pigment dispersion(17 percent active, available from Sun Chemicals) diluted with 110 gramsof deionized water. To the resulting homogenized latex/pigment blend,2.4 grams of 10 percent PAC (polyaluminum chloride) solution dilutedwith 24 grams of 0.02N HNO₃ was added dropwise to cause a flocculationof the PY74 yellow pigment, 8.37 percent by weight, the POLYWAX 725®,12.55 percent by weight, the resin poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate), 78.91 weight percent, and 0.17 weightpercent of the PAC. After the addition was complete, homogenization wascontinued for an additional 2 minutes to form a creamy blend with anaverage particle size by volume of 2.59 and with a GSDv of 1.21. Thecreamy blend was then transferred into a 2 liter glass reactor andstirred at 350 rpm, while being heated to about 52° C. to about 53° C.Particle growth was monitored during heating. When the particle sizediameter of the solids by volume was equal to 4.79 (GSDv=1.20), 100grams of polymer latex poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-trimethylolpropane triacrylate) (EP444) wasadded into the slurry mixture in the glass reactor. Particle growth wascontinuously monitored during heating. When the particle size diameterof the solids by volume was equal to 5.49 (GSDv=1.22), the pH of theslurry was adjusted. The slurry was comprised of about 16 weight percentof toner and of about 84 weight percent of water. The toner wascomprised of about 6 percent of PY74 yellow pigment, about 9 percent ofPOLYWAX 725®, about 0.2 weight percent of PAC, about 56.5 percent byweight of the resin poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-urethane acrylate), and about 28.3 percentby weight of resin poly(styrene-butyl acrylate-acrylicacid-β-carboxyethyl acrylate-trimethylolpropane triacrylate). The totalamount of the toner components was about 100 percent. The pH wasadjusted to 7.5 by the addition of a 2 percent NaOH solution and thespeed in the reactor was reduced to 200 rpm. After ½ hour of stirring at53° C., the temperature in the reactor was increased to 95° C. After 1hour of heating at 95° C., the pH of the slurry was adjusted to 4.3 andthe heating was continued for an additional 5 hours. Thereafter, thereactor contents were cooled down to about room temperature, throughoutthe Examples, about 23° C. to about 25° C. and were discharged. A 16percent solids slurry of 5.57 micron black toner particles withGSDv=1.21 was obtained. The resulting toner product was comprised ofabout 6 percent of PY74 yellow pigment, about 9 percent of POLYWAX 725®,about 0.2 weight percent of PAC, about 56.5 percent by weight of theresin poly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate),and about 28.3 percent by weight of the resin poly(styrene-butylacrylate-acrylic acid-β-carboxyethyl acrylate-trimethylolpropanetriacrylate), and wherein the total amount of the toner components wasabout 100 percent. The toner particles were then washed with deionizedwater five times and dried.

COMPARATIVE EXAMPLE I 5.6 Micron Yellow Toner Particles Generated by PACA/C Process

The poly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate)polymer latex of Latex Example (I) (EP406) above was utilized in anaggregation/coalescence (A/C) process to produce 5.6 micron (volumeaverage diameter) particles with a narrow size distribution.

500 grams of deionized water was placed in a stainless steel beaker andhomogenized at 5,000 rpm, while there was added 300 grams of latexpoly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate)(EP406), 37.16 grams of the polyethylene wax POLYWAX 725® dispersion (Mwof 725, 31 percent active, available from Baker-Petrolite Company)followed by the addition of 38.3 grams of PY74 yellow pigment dispersion(17 percent active, available from Sun Chemicals) diluted with 110 gramsof deionized water. To the resulting homogenized latex/pigment blend,2.4 grams of 10 percent PAC (polyaluminum chloride obtained from AsadaCompany of Japan) solution diluted with 24 grams of 0.02N HNO₃ was addeddropwise to cause a flocculation of the PY74 yellow pigment, 6 percentby weight, the POLYWAX 725®, 9 percent by weight, the resin, 84.88weight percent, and 0.12 weight percent of the PAC. After the additionwas complete, homogenization was continued for an additional 2 minutesto form a creamy blend with an average particle size by volume of 2.63and with a GSDv of 1.20. The creamy blend was then transferred into a 2liter glass reactor and stirred at 350 rpm, while being heated to about52° C. to about 53° C. Particle growth was monitored during heating.When the particle size diameter of the solids by volume was equal to5.54 (GSDv=1.21), the pH of the slurry was adjusted. The slurry wascomprised of about 16 weight percent of toner and of about 84 weightpercent of water. The toner was comprised of about 6 percent of PY74yellow pigment, about 9 percent of POLYWAX 725®, about 0.2 weightpercent of PAC and about 84.8 percent by weight of the resinpoly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate). Thetotal amount of the toner components was about 100 percent. The pH wasadjusted to 7.5 by the addition of a 2 percent NaOH solution and thespeed in the reactor was reduced to 200 rpm. After ½ hour of stirring at53° C., the temperature in the reactor was increased to 95° C. After 1hour of heating at 95° C., the pH of the slurry was adjusted to 4.3 andthe heating was continued for an additional 5 hours. Thereafter, thereactor contents were cooled down to about room temperature, throughoutthe Examples, about 23° C. to about 25° C. and were discharged. A 16percent solids slurry of 5.64 micron black toner particles withGSDv=1.21 was obtained. The resulting toner product was comprised ofabout 6 percent of PY74 yellow pigment, about 9 percent of POLYWAX 725®,about 0.2 weight percent of PAC and about 84.8 percent by weight of theresin poly(styrene-butyl acrylate-acrylic acid-β-carboxyethyl acrylate),and wherein the total amount of the toner components was about 100percent. The toner particles were then washed with deionized water fivetimes and dried.

Evaluation

Yellow toners of the above Examples I to III and Comparative Example Iwere evaluated by forming images in a MajectiK 5765 copier in both Xerox4024 paper and Xerox 3R3108 transparency, and fusing the images usingImari-MF free belt nip fuser. After the fusing step, the yellow tonerimages of Examples I to III and Comparative Example I demonstrated poorrub resistance. All the images were smeared after 10 double rubs withtoluene laden cloth.

Yellow toners of the above Examples I to III and Comparative Example Iwere evaluated by forming images in a MajectiK 5765 copier in both Xerox4024 paper and Xerox 3R3108 transparency, and fusing the images usingImari-MF free belt nip fuser. After the fusing step, these yellow tonerimages were exposed to a UV curing system (Loctite Zeta 7400 UV Oven byLoctite Corporation), with UV lamps of about 30 mW/cm² at the wavelength365 nm. The exposure time is set at about 3 minutes. The radiationtemperature was maintained between 25 to 30° C. The post-cured yellowtoner images of Examples I to III demonstrated excellent rub resistance.The images resisted 20 double rubs with toluene-damped cloth. Incontrast, the yellow toner images of Comparative Example I demonstratedpoor rub resistance. The yellow toner images of Comparative Example Iwere smeared after 5 double rubs with toluene-damped cloth.

Images on polymer substrates and packaging cardboard were performed onbench development setup and fusing fixture. The above-mentioneddeveloper made for MajectiK 5765 copier was incorporated into anelectrostatographic imaging device with a cascade development zone. Thesubstrates used for the development were brown paper cardboard and a fewdifferent polymer substrates such as polyethylene terephthalate (PET),high-density polyethylene (HDPE), polypropylene (PP), and Nylon®. Afterabout 1.4 gm/cm² solid density was developed, the substrate and thetoner were fused using a silicone rubber fuser roll from a Xerox 5028machine. The surface temperature of fuser roll was set at about 400° F.and the speed was set at about 120 rpm. After the fusing step, theseyellow toner images were exposed to a UV curing system and the rubbingtests were performed as mentioned above. All images made from toner inExamples I to III on polymer substrates and packaging cardboardsresisted 20 double rubs with toluene-damped cloth, which showedimprovement in solvent resistance after UV curing compared to non-UVcurable toner images made from Comparative Example I. Polyethylene andpolypropylene films showed equivalent development as PET films as thesubstrates. PE and PP films are excellent substrates for toner fusedbelow 120° C.

The exemplary embodiment has been described with reference to thepreferred embodiments. Obviously, modifications and alterations willoccur to others upon reading and understanding the preceding detaileddescription. It is intended that the exemplary embodiment be construedas including all such modifications and alterations insofar as they comewithin the scope of the appended claims or the equivalents thereof.

1. A toner composition comprised of an optional colorant, a polymergenerated from styrene and an acrylate, and a UV light curable acrylateoligomer.
 2. The toner composition of claim 1 wherein said UV lightcurable acrylate oligomer is present in said toner composition in anamount of from about 1 to about 15 percent by weight.
 3. The tonercomposition of claim 2 wherein said UV light curable acrylate oligomeris present in said toner composition in an amount of from about 2 toabout 10 weight percent.
 4. The toner composition of claim 1 whereinsaid UV light curable acrylate oligomer is selected from the groupconsisting of epoxy-acrylates, polyester-acrylates, acrylate oligomers,polyether acrylates, polyurethane acrylates, and combinations thereof.5. The toner composition of claim 4 wherein said UV light curableacrylate oligomer is an epoxy-acrylate.
 6. The toner composition ofclaim 4 wherein said UV light curable acrylate aligomer is apolyester-acrylate.
 7. The toner composition of claim 4 wherein said UVlight curable acrylate oligomer is an acrylate oligomer.
 8. The tonercomposition of claim 4 wherein said UV light curable acrylate oligomeris a polyether acrylate.
 9. The toner composition of claim 4 whereinsaid UV light curable acrylate oligomer is a polyurethane acrylate. 10.The toner composition of claim 4 wherein said UV light curable acrylateis said polyurethane acrylate.
 11. The toner composition of claim 10wherein said polyurethane acrylate is selected from the group consistingof polyether-urethane acrylate, polyester-urethane acrylate, andcombinations thereof.
 12. The toner composition of claim 10 wherein saidpolyurethane acrylate is a polyurethane end capped with an acrylatemoiety.
 13. The toner composition of claim 12 wherein said acrylatemoiety is hydroxyethyl acrylate.
 14. The toner composition of claim 10wherein said polyurethane acrylate is formed from a polyurethaneoligomer.
 15. The toner composition of claim 14 wherein saidpolyurethane oligomer is prepared from an aliphatic diisocyanate. 16.The toner composition of claim 15 wherein said aliphatic diisocyanate isselected from the group consisting of hexamethylene diisocyanate,cyclohexane diisocyanate, diisocyclohexylmethane diisocyanate,isophorone diisocyanate, and combinations thereof.
 17. The tonercomposition of claim 16 wherein said aliphatic diisocyanate isisophorone diisocyanate.
 18. The toner composition of claim 11 whereinsaid polyurethane acrylate is polyester-urethane prepared from adipicacid and neopentyl glycol.
 19. The toner composition of claim 1 whereinsaid UV light curable acrylate oligmer is selected from the groupconsisting of tris (2-hydroxy ethyl) isocyanurate triacrylate;ethoxylated pentaerythritol tetraacrylate; pentaerythritol tetracrylate;dipentaerythritol pantaacrylate; chlorinated polyester acrylate; aminemodified epoxy acrylate; aromatic urethane acrylate; polyurethaneacrylate laromer; aromatic urethane triacrylate; aliphatic diacrylateoligomer; aliphatic urethane diacrylate; aromatic urethane diacrylate;and combinations thereof.
 20. The toner composition of claim 1 furthercomprising a photoinitiator.
 21. The toner composition of claim 20wherein said photoinitiator is present in said toner composition in anamount of from about 0.1 to about 5 percent by weight.
 22. The tonercomposition of claim 21 wherein said photoinitiator is present in saidtoner composition in an amount of from about 0.5 to about 2 percent byweight.
 23. The toner composition of claim 20 wherein saidphotoinitiator is selected from the group consisting of2-hydroxy-2-methyl-1-pheyl-1-propanone; 1-hydroxycyclohexylphenylketone; 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one;2,2-dimethoxy-2-phenylacetophenone;2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone; andcombinations thereof.
 24. The toner composition of claim 20 wherein saidphotoinitiator is selected from the group consisting of2-hydroxy-2-methyl-1-phenyl-propan-1-one (HMPP); 2,4,6-trimethyl benzoyldiphenyl phosphine oxide (TPO); 50:50 Blend of HMPP and TPO;2-methyl-1[4-(methylthio)phenyl]-2-morpholino propan-1one (MMMP);2,2-dimethoxy-2-phenyl acetophenone (BDK); 2,4,6-trimethyl benzoyldiphenyl phosphine oxide (Lucirin TPO); alpha hydroxyketone;2-hydroxy-2-methyl-phenyl-1-propane; and combinations thereof.
 25. Thetoner composition of claim 1 wherein said acrylate is selected from thegroup consisting of butyl acrylate, carboxyethyl acrylate, andcombinations thereof.
 26. A toner composition comprised of a colorantand a polymer generated from a UV curable cycloaliphatic epoxide. 27.The toner composition of claim 26 wherein said cycloaliphatic epoxide isselected from the group consisting of 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate; bis-(3,4-epoxycyclohexyl) adipate;and combinations thereof.
 28. The toner composition of claim 26 furthercomprising a photoinitiator.
 29. The toner composition of claim 28wherein said photoinitiator is selected from the group consisting ofmixed triarylsulfonium hexafluoroantimonate salts, mixedtriarylsulfonium hexafluorophosphate salts, and combinations thereof.30. A method of forming a UV curable toner composition, said methodcomprising: preparing a latex of a polymer formed from styrene, butylacrylate, 2-carboxymethyl acrylate, and a UV curable acrylate; combiningsaid latex with a pigment and an optional wax to form a first system;adding flocculant to said first system to induce aggregation and formtoner precursor particles dispersed in a second system; heating saidtoner precursor particles to a temperature greater than the glasstransition temperature of said polymer to form toner particles; washingsaid toner particles; and drying said toner particles.
 31. The tonercomposition produced by the method of claim
 30. 32. A method of forminga UV curable toner composition comprising: mixing a latex containing apolymer formed from styrene, butyl acrylate, a carboxymethyl acrylate,and a UV curable acrylate with a colorant and a wax; adding a flocculentto optionally induce aggregation and form toner precursor particlesdispersed in a second mixture; heating said toner precursor particles toa temperature equal to or about higher than the glass transitiontemperature of said polymer to form toner particles; and optionallywashing said toner particles; and optionally drying said tonerparticles.
 33. The toner composition produced by the method of claim 32.34. The method of claim 32 wherein said flocculant is a photoinitiator.35. A method of forming a UV curable toner composition, said methodcomprising: mixing a latex of a polymer formed from styrene, butylacrylate, and carboxymethyl acrylate, with a pigment and a wax to form afirst system; adding a flocculant to said first system to induceaggregation and form toner precursor particles dispersed in a secondsystem; adding a UV curable acrylate to said second system to form ashell on said toner precursor particles; heating said toner precursorparticles to a temperature greater than the T_(g) of said shell to formtoner particles; optionally washing said toner particles; and optionallydrying said toner particles.
 36. The method of claim 35 wherein saidflocculant includes a photoinitiator.
 37. The toner composition producedby the method of claim
 35. 38. A method for printing and/or coating of asubstrate, using at least one curable coating, said method comprising:providing a substrate; providing a toner composition including (i) apolymer generated from styrene and acrylate selected from the groupconsisting of butyl acrylate, carboxyethyl acrylate, and a UV lightcurable acrylate oligomer, (ii) and optionally, a colorant; applyingsaid toner composition on said substrate; and curing said tonercomposition by exposure to UV light.
 39. The method of claim 38 whereinsaid substrate is selected from the group consisting of paper,cardboard, plastic, foil, metal, and combinations thereof.
 40. A methodfor printing and/or coating of a substrate, using at least one curablecoating, said method comprising: providing a substrate; providing atoner composition including (i) a polymer generated from a UV curablecycloaliphatic epoxide (ii) and a colorant; applying said tonercomposition on said substrate; and curing said toner composition byexposure to UV light.
 41. The method of claim 40 wherein said substrateis selected from the group consisting of paper, cardboard, plastic,foil, metal, and combinations thereof.